Psychostimulants BASICS

Question 1

general drugs for ADHD

Answer 1

• Amphetamines/Amphetamine-like agents (methylphenidate) (IR or XR)
• Atomoxetine (NSRI)
• Guanfacine and Clonidine (alpha-2 agonists)

Question 2

amphetamines MOA

Answer 2

(ADHD)
Stimulate monoamine neurotransmitters (promote release of biogenic amines from storage sites)

Prevents storage of dopamine in vesicles in the axon terminal.
High levels of dopamine.
Transporters push domamine into synaptic cleft due to high concentration.

Question 3

Why are there cardiovascular concerns with amphetamines?

Answer 3

(ADHD)
Stimulants –> stimulate NE release.
NE most readily stimulates Alpha-1 receptors –> increased vasoconstriction, increased peripheral resistance –> increased blood pressure

Question 4

atomoxetine (strattera) use and MOA

Answer 4

ADHD

Selective inhibitor of NE transport (NSRI)
NONSTIMULANT

Blocks NE reuptake so it is available in synapse for longer.

Question 5

Guanfacine, Clonidine use/MOA

Answer 5

ADHD

MOA: alpha-2 receptor agonists –> prevents release of NTs (MOA for ADHD unclear)

Question 6

drugs for treatment of sleepiness, narcolepsy, cataplexy

Answer 6

Caffeine
Modafinil
Gammahydroxybutyrate

Question 7

caffeine is an analog to ________

Answer 7

caffeine is an analog to ADENOSINE

Question 8

caffeine mechanism

Answer 8

(sleepiness)
MOA: adenosine receptor antagonist (same shape, but does not cause same effect, just blocks site)

Adenosine binding to PRESYNAPTIC receptor:

• closes Ca++ channels
• decreased NT release

Adenosine binding to POSTSYNAPTIC receptor:

• open K+ channel
• hyperpolarizes cell
• decreased response to stimuli

If BLOCKED:

• increased NT release
• increased response to stimuli

Question 9

mechanism of Modafinil (provigil)

Answer 9

Blocks dopamine transporter (dopamine available in synapse longer).
Increases synaptic dopamine (DSRI).
Not entirely clear how it relates to sleep

Question 10

Modafinil uses

Answer 10

Excessive sleepiness.

• narcolepsy
• shift work
• obstructive sleep apnea

Question 11

use of GHB (gammahydroxybutyrate)

Answer 11

Cataplexy (low muscle tone –> falls).
Narcolepsy.

Promotes profound sleep at night, so less likely to fall asleep the next day.

Question 12

MOA of gammahydroxybutyrate (GHB)

Answer 12

(narcolepsy, cataplexy)

• potent enhancer of GABA (powerful sedative)
• exhibits GABA and dopamine-like effects

date rape drug (conscious sedation)

Question 13

names/types of anorexiants

Answer 13

• phentermine: NE transporter inhibition
• lorcaserin: 5HT(2C) receptor agonist
• bupropion + naltrexone: DA and NE reuptake inhibitor and opioid receptor antagonist

Question 14

anorexiants are used to

Answer 14

Treat obesity.
Moderate weight gain.

Have rebound effect when stop using so beware.

Question 15

phentermine (lonamin) MOA

Answer 15

anorexiant

NE transporter inhibition

• NE stays in synapse longer, acts as stimulant
• sympathetic NS activated, parasympathetic suppressed

Question 16

lorcaserin (belviq) use, MOA

Answer 16

anorexiant

5HT(2C) [serotonin] receptor agonist

• more serotonin produced
• change in hypothalamus
• less hungry

Question 17

burpropion + Naltrexone use, MOA

Answer 17

Anorexiant

DA and NE reuptake inhibitor.
Opioid receptor antagonist.

Question 18

Order of pharmacological tx for ADHD

Answer 18

1. stimulants (methylphenidate or amphetamine)
2. stimulants (try another subtype)
3. atomoxetine (Strattera)
4. buproprion
5. tricyclic antidepressants
6. alpha agonists